1. Field of the Invention
The present invention is directed to computer systems. More particularly, it is directed to graphical image processing.
2. Description of the Related Art
Three-dimensional (3D) graphics rendering is a process of generating an image from a 3D model, generally by means of software programs and/or graphics hardware. The model is generally a description of 3D objects in a strictly defined language or data structure and may contain geometry, viewpoint, texture and lighting information. A 3D model may include polygons, such as triangles, representing the surface of the 3D model. The polygons from the 3D model may be drawn, rendered or rasterized onto a two-dimensional (2D) surface, such as a computer screen.
Large complex images may be defined using layers. Layers are independent images that can be manipulated as if each layer were an independent image. Each layer only forms a part of the final image. Layers are like transparencies stacked one on top of one another. Each layer may have different objects, images and effects. Layers allow users to work on separate images in order to modify sections without changing the entire image. When the layers are stacked, the images appear as if they are all a single image. The final image will be made up from all of the layers within the image depending on the order of the layers.
When rendering a scene, the resolution of the image traditionally was limited to the computer screen size, but there may be times when a higher resolution image is needed. Higher resolution images may be divided into multiple image tiles that each fit in the graphics frame buffer. The image may be rendered tile by tile, with the results saved into off screen memory, a MIP map, or even a file. By subdividing the image to be rendered into a grid, and then rendering each region separately, a series of partial images can be generated that may be tiled onto a larger image surface to form the final image.